.overlay {
    position:fixed;
    display:block;
    width:100%;
    height:100%;
    top:0;
    left:0;
    background-color:rgba(74,74,74,.8);
    z-index:99999;
}

.spinner {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
}